Boiling in heads
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Boiling in heads
Found a simalar topic through search but found no answers.
84 F250 300ci 1bbl
Had some trouble with retarded timing, got the exhaust manifold quite hot. At the time the coolant in the heads was boiling, but now that my timing is correct the coolant will still boil in the head, but only after I shut the vehicle down. Temp gauge runs normal for as long as the vehicle runs, but a minute or so after I shut the truck off a boiling sound comes from the head, and the temp gauge goes up a little (Key on of course) The temp sensor is mounted right after the thermostat. Just replaced the thermostat, thermo housing, and drained and refilled at the radiator.
First I'll make sure I didn't put the thermo in backwards , but if anyone has any other idea's they'd be appreciated.
84 F250 300ci 1bbl
Had some trouble with retarded timing, got the exhaust manifold quite hot. At the time the coolant in the heads was boiling, but now that my timing is correct the coolant will still boil in the head, but only after I shut the vehicle down. Temp gauge runs normal for as long as the vehicle runs, but a minute or so after I shut the truck off a boiling sound comes from the head, and the temp gauge goes up a little (Key on of course) The temp sensor is mounted right after the thermostat. Just replaced the thermostat, thermo housing, and drained and refilled at the radiator.
First I'll make sure I didn't put the thermo in backwards , but if anyone has any other idea's they'd be appreciated.
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Joined: May 2002
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From: Broken Arrow, OK
It sounds like the radiator cap (or some other component) may not be holding pressure. The coolant is supposed to be under about 15psi pressure at operating temperature, if it isn't under pressure the coolant will boil at a lower temp. It is also possible that somthing is causing excessive cylinder head temp, but that should be reflected on the gauge.
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Joined: Feb 2004
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From: Northwest
Maybe you have air trapped in the system ? Try taking the thermostat out and drilling a 3/16 hole in the outer frame of the thermostat........ and when you reinstall it make sure the hole is at 12 o'clock. This will act as an air bleed hole to insure that you don't have any chance of an air pocket developing.
If your still having problems after that ......... pehaps take off the water pump and inspect it to make sure the impellers have not disinigrated.
If your still having problems after that ......... pehaps take off the water pump and inspect it to make sure the impellers have not disinigrated.
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Just did a cooling system pressure test, I could here a leak at the top of the radiator. I guess that would kill my pressure then.
But I'm not convinced it causes the violent boiling a little after I turn off the engine. If I run the engine a little after initially shutting it down and hearing the boil, it will stop again.
But I'm not convinced it causes the violent boiling a little after I turn off the engine. If I run the engine a little after initially shutting it down and hearing the boil, it will stop again.
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Joined: Nov 2002
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From: Kentucky
Running it for a short period of time after the original shut down moves the hot coolant out of the engine and the cooler coolant out of the radiator into the engine..I believe that when you get the radiator leak fixed, And the pressure where it should be, it will do better.
Water boils at a lower temp than the proper coolant and water mix, Pressure will also raise the boiling point of the mix..
Do you have the proper mix or are you running just water?
Did you pressure test the CAP in addition to the radiator??
The caps go bad and lose pressure too..
I hope this helps
ftwfred
Water boils at a lower temp than the proper coolant and water mix, Pressure will also raise the boiling point of the mix..
Do you have the proper mix or are you running just water?
Did you pressure test the CAP in addition to the radiator??
The caps go bad and lose pressure too..
I hope this helps
ftwfred
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